#include<bits/stdc++.h>
#include<ext/pb_ds/assoc_container.hpp>
#include<ext/pb_ds/tree_policy.hpp>
#include<ext/rope>
#define rep(i,l,r) for(int i=(l),i##end=(r);i<=i##end;++i)
#define per(i,r,l) for(int i=(r),i##end=(l);i>=i##end;--i)
#define int long long
#define double long double
#define pii pair<int,int>
#define fi first
#define se second
#define pb push_back
#define rbtree(way) tree<way,null_type,less<way>,rb_tree_tag,tree_order_statistics_node_update>
using namespace std;
using namespace __gnu_cxx;
using namespace __gnu_pbds;
const int maxn=1e6+10,maxm=1e6+10,mod=998244853,inf=1e9;
inline int ksm(int x,int k,int mod=mod){
	int ans=1;
	for(;k;k>>=1,x=x*x%mod) if(k&1) ans=ans*x%mod;
	return ans;
}

int n,a[maxn];

signed main(){
	freopen("trade.in","r",stdin),freopen("trade.out","w",stdout);
	ios::sync_with_stdio(0),cin.tie(0),cout.tie(0);
	cin>>n;
	rep(i,1,n) cin>>a[i],a[i]+=a[i-1];
	if(a[n]<n) cout<<0;
	else cout<<1;
	return 0;
}